The present invention relates to vibrating linear actuators used in portable information terminals.
A vibrating paging-function is now essential to portable information terminals such as cellular phones. The market requires vibration generators to be thinner because the portable information terminals have become slimmer and slimmer. At the same time, the vibration generators are demanded to be surface-mounted on a circuit board like other electronic components because the portable information terminals need a higher packing density.
FIG. 14 shows a conventional vibration generator which uses a rotating motor including unbalancing weight 25. This vibration generator generates vibrations in parallel with the circuit board; however, a user feels vibrations vertical to the circuit board more sensitively. Thus the market prefers vibrations vertical to the circuit board.
FIG. 15 shows another conventional vibration generator that uses voice coil 42 and is to be surface-mounted on a circuit board. This vibration generator is a multifunctional vibrating actuator that generates vibrations vertical to the circuit board, and works as a speaker and a buzzer. However, since it is used as a sound source, it should not be closed with a cover, and diaphragm 44 that produces sound is not resistant enough to heat. This vibration generator thus does not fit to reflow soldering.
The present invention addresses the problems discussed above, and aims to provide a vibrating linear actuator that vibrates vertically to the circuit board and is resistant enough to heat.
The vibrating linear actuator of the present invention comprises the following elements:
a mover including a permanent magnet;
a stator including coils that generate vibrating magnetic field which vibrates the mover;
a base on which the stator is mounted;
a cover that is provided on the base and covers the mover and the stator; and
an electrode prepared on the surface of one of the base and the cover and electrically coupled to the coils.